Electrical connector



Sept. 10, 1940; E. KRAMER 2,214,081

ELECTRICAL CONNECTOR Filed Nov. 26, 1938 10a Zdmwime];

INVENTOR.

Patented Sept. 10, 1940 UNITED STATES- PATENT OFFICE 2,214,081ELECTRICAL CONNECTOR Ewal d Kramer, Dresden, Germany ApplicationNovember 26, 1938, Serial No. 242,626 In Germany December 17, 1937 6-Claims. (Cl. 173361) nector of this type having relatively movablecontact elements (pins or sleeves) such that they will always be easilyengageable with the contact elements of the co-acting member without anypreliminary hand adjustment but under conditions positively ensuringgood electrical contact combined with adequate frictional detentionagainst accidental disengagement.

In accordance-with the invention a member of an electric plug-and-socketconnector com-'- prises an insulating base, spaced contact elements,means mounting the contact elements in the base for relative rockingmovement in parallel planes to and from parallelism, and meansresiliently urging the contact elements from parallelism, themountingmeans being disposed to enable practically constant spacing of the tipsof the contact elements during the relative rocking movement.

The arrangement is such that the contact elefll ments, during theirengagement with the fixedly located contact elements of the co-actingmember of theconnector, automatically assume parallelism under theguidance of said fixedly lo,- cated elements and also provide goodelectric contact therewith under the resilient pressure tending alwaysto bias them from parallelism.

The said mounting means for at least one of the contact elements mayinclude a'roller turnably mounted in the base with its axis so disposedI as to enable the required substantially constant spacing of the tipsof the contact elements throughout the permitted turning movement of theroller. v

Preferably, however, the mounting means for 40 each of the contactelements includes a roller iournalled in the base, the axes of therollers being in parallel and offset.

Other features of the invention appear from what follows? By way'ofexample and for the purpose of better explaining the invention; oneembodiment thereof as appliedto the plug member of an electricplug-and-socket connector is illustrated on w the accompanying drawingto which reference will now be made.

Fig. 1 represents a section through the-"plug,

on the broken line 1-1 of Fig. 2', with the contact pins shown inelevation. l

Fig. 2 is a plan, th e cover being omitted.

Fig. 3 is a side elevation ofone of the springs which coact with thecontactpins.

l denotes the plug body or base of any suitable insulating material,such as synthetic resinous composition, and 2 denotes its cover. The 5contact pins are designated 3 and 4. They are connected, by screwing orpress fitting or the like, to rollers 5 and 6 respectively. Theserollers are mounted for turning movement in bearings provided in thebase I and are retained by 10 the cover 2'. As will be seen from Fig. 2,they are mounted with their axes parallel and displaced to oppositesides of the parallel diameter of the base. The pins 3, 4 haveextensions l5 and I 6 respectively projecting inwardly of the base, and15 blade springs l1 and I8 bear against these extensions at oppositesides for the purpose of obtaining the desired action, namely, oppositemovement of the pins 3, 4 in parallel planes to inclined, non-alignedpositions. The pins 3, 4 project through elongated openings I9 and 20 inthe cover 2. r

The rollers 5, 6 are shown provided with bores I and 8 for the receptionof the ends 9 and III of the cable II which is introduced into the basethrough a bore I2. The, ends of the cable are secured in the bores 1 and8 by grub screws l3 and I4. 7

When the plug is not engaged with its co-acting socket (not shown) thepins 3, 4 assume oppositely inclined (non-parallel) positions under theaction of the springs l1, Ill. The inclination may be such that arocking movement in parallel planes about their roller axes through 10to 12 is sufficient to bring them into parallelism. When the pins are inthe inclined position the distance apart of their tips, along the linea-b in Fig. 2, is substantially the same as the distance apart of theintersections of the pin axes with the roller axes, along the'line c-din Fig 2, 40 and corresponds to the spacing of the sleeves fixedlylocated in the co-acting socket. In other words, the projected centresof the pintips and of the pin bases intercept a circle whose diameterpractically corresponds to the, spacing of a the sleeves in the socketto be engaged.

Therefore, the tips of the pins, which need only have a loose slidingfit in the-sleeves, can very easily be entered into the sleeves. As thepins are inserted they rock intoparallelism under the guidance of thesleeves since the plug twists or turns slightly until the linec-dbecomes coincident with the projection of line a--b, when the 1 pinsattain parallelism and are fully inserted in the sleeves: It will beunderstood that duringthe 68 insertion and during the consequent rockingmovement of the pins the rollers 5, 6 carrying them turn slightly ontheir respective axes.

Thus, before, during and after insertion, the tips of the pins are atpractically the same distance apart corresponding to the spacing of thesleeves in the socket.

When the pins are inserted in the sleeves of the socket good electricalcontact is positively curement offers the advantage that fatigue of,

the cable ends due to the movements of the contact pins is avoided.Moreover, if desired, helical springs may surround the rollers 5, 6 forconducting the current from the ends of the flex to the contact pins 3,4.

Further, instead of blade springs l1 and It! for biasing the contactpins 3, 4, other forms of springs, such as helical springs, may beemployed.

Many other modifications within the invention will be apparent. Forexample, it will be appreciated that only one of the contact pins may bemounted as described for rocking movement to and from alignment with theother and under conditions enabling practically constant spacing of thepin tips during such movement.

Finally, it will also be apparent that although the invention has beenparticularly described with reference to the plug member of aplugand-socket connector, it can equally well be applied to the socketmember of such a connector, in which case the contact sleeves would bemounted for relative rocking movement in the manner herein describedwith reference to the plug pins 3, 4.

I claim:

1. A member of an electric plug-and-socket connector, comprising aninsulating base, spaced. contact elements, means mounting the contactelements in the base for relative rocking movement in parallel planes toand from parallelism, and resilient means constantly urging the contactelements from parallelism, the mounting means having axes substantiallydisplaced relatively a distance equal to the range of movement of thetips of the contact elements to maintain substantially constant spacingof the tips of the contact elements throughout the relative rockingmovement.

2. A member of an electric plug-and-socket connector, comprising aninsulating base, spaced contact elements, means mounting the contactelements in the base for relative rocking movement in parallel planes toand from parallelism, the mounting means for at least one of the contactelements including a roller journalled in the base with its axissubstantially displaced from the mounting means for the other of thecontact elements a distance equal to the range of movement of the tipsof the contact elements to maintain substantially constant spacing ofthe tips of the contact elements throughout the relative rockingmovement, and resilient means constantly urging the contact elementsfrom parallelism.

3. A member of an electric plug-and-socket connector, comprisingan'insulating base, spaced contactelements, means mounting the contactelements in the base for relative rocking movement in parallel planes toand from parallelism, and resilient means constantly urging the contactelements from parallelism, the mounting means for the contact elementsincluding rollers journalled in the base with their axes parallel andsubstantially offset a distance equal to the range of movement of thetips of the contact elements.

4. A member of an electric plug-and-socket connector as claimed in claim2, the said roller mounted contact element extending through the rollerto form a two-armed lever having as its pivotal axis that of the roller,and the said resilient means acting on one of said arms.

5. A member of an electric plug-and-socket connector as claimed in claim3, each of the said roller mounted contact elements extending throughits roller to form a two-armed lever having as its pivotal axis that ofthe roller, and the said resilient means acting on one of the arms ofeach lever.

6. An electrical connector plug comprising an insulating base, tworollers turnably mounted in the base with their axes parallel andoifset, contact pins projecting radially from the rollers beyond thebase in two parallel planes normal to the roller axes, extensions on thepinsprojecting radially from the rollers within the base, and resilientmeans within the base bearing on the extensions to rock the pins tooppositely inclined positions in said parallel planes, the offset dis--stance of said parallel roller axes being substantially equal to therange of movement of the outer tipsof said contact pins.

EWALD

